Sequence hybrid biological reactor （SHBR） was proposed, and some key control parameters were investigated for nitrogen removal from wastewater by simultaneous nitrification and denitrification （SND） via nitrite. S...Sequence hybrid biological reactor （SHBR） was proposed, and some key control parameters were investigated for nitrogen removal from wastewater by simultaneous nitrification and denitrification （SND） via nitrite. SND via nitrite was achieved in SHBR by controlling demand oxygen （DO） concentration. There was a programmed decrease of the DO from 2.50 mg·L^-1 to 0.30 mg·L^-1, and the average nitrite accumulation rate （NAR） was increased from 16.5% to 95.5% in 3 weeks. Subsequently, further increase in DO concentration to 1.50 mg·L^-1 did not destroy the partial nitrification to nitrite. The results showed that limited air flow rate to cause oxygen deficiency in the reactor would eventually induce only nitrification to nitrite and not further to nitrate. Nitrogen removal efficiency was increased with the increase in NAR, that is, NAR was increased from 60% to 90%, and total nitrogen removal efficiency was increased from 68% to 85%. The SHBR could tolerate high organic loading rate （OLR）, COD and ammonia-nitrogen removal efficiency were greater than 92% and 93.5%, respectively,, and it even operated under low DO concentration （0.5 mg·L^-1） and maintained high OLR （4.0 kg COD·m^-3·d^-1）. The presence of biofilm positively affected the activated sludge settling capability, and sludge volume index （SVI） of activated sludge in SHBR never hit more than 90 ml·L^-1 throughout the experiments.展开更多
The study presented the method for isolating the heterotrophic nitrifiers and the characterization of heterotrophic nitrification. When influent Ammonia nitrogen concentration was 42. 78 - 73. 62 mg/L. The average amm...The study presented the method for isolating the heterotrophic nitrifiers and the characterization of heterotrophic nitrification. When influent Ammonia nitrogen concentration was 42. 78 - 73. 62 mg/L. The average ammonia nitrogen removal rate was 81.32% from the bioceramics reactor. Sodium acetate and ammonium chloride were used as carbon and nitrogen source. The COD removal rates by microorganisms of strain wgy21 and wgy36 were 56.1% and 45.45%, respectively. The TN removal rates by microorganisms of strain wgy21 and wgy36 were 65.85% and 67. 98%, respectively. At the same time, the concentration of ammonium nitrogen was with the removal rates of 75.25% and 84.96%, and it also had the function of producing NO2 - N. Sodium acetate and sodium nitrite were used as carbon and nitrogen source. Through the 12 days of the aerobic culture, the COD femoral rates by microorganisms of strain wgy21 and wgy36 were 29.25% and 22.08%, respectively. NO2 -N concentration decreased slowly. Comparison, similarity of wgy21 and many Acinetobacter sp. ≥99%, similarity of wgy36 and many Acinetobacter sp. ≥99%. Refer to routine physiologicalbiochemical characteristic determination, further evidences showed that wgy21 and wgy36 belong to Acinetobacter sp., respectively.展开更多
A method about the isolation of heterotrophic nitrosobactria and the characteristics of heterotrophic nitrosobactria were studied.It can be seen from the fluorescence in situ hybridization results of the bio-membrane ...A method about the isolation of heterotrophic nitrosobactria and the characteristics of heterotrophic nitrosobactria were studied.It can be seen from the fluorescence in situ hybridization results of the bio-membrane sample from the bio-ceramic reactor,the spots of green nitrosobacteria are obviously more than those of orange nitrobacteria.Two heterotrophic nitrobacteria were isolated from the bio-ceramic reactor.By sequencing 16SrDNA and establishing the phylogenic tree,they were identified physiologically and biochemically as Pseudomonas sp..After 12 d,the COD removal efficiency of wgy55 and wgy68 were 45.03% and 50.85%,the NH4-N removal efficiency of them were 80.12% and 85.93%,and the TN removal efficiency of them were 69.71% and 64.7%.The final concentration of NO2-N of wgy55 and wgy68 was 0.753 mg/L and 0.601 mg/L,and that of NO3-N was 3.21 mg/L and 3.38 mg/L.These results show that wgy55 and wgy68 have the capability of nitrification and they are heterotrophic nitrobacteria.展开更多
This study was conducted to verify and discuss the denitrifying dephosphatation under different levels of nitrate concentration and retention time of anoxic/aerobic process in a Sequencing Batch Reactor (SBR). The res...This study was conducted to verify and discuss the denitrifying dephosphatation under different levels of nitrate concentration and retention time of anoxic/aerobic process in a Sequencing Batch Reactor (SBR). The results of tests demonstrated that there were two kinds of phosphorus-accumulating organisms (PAOs) in the biological excess phosphorus removal (BEPR) system. One was non-DNPAOs that could only use oxygen as terminal electron acceptors, the other was denitrifying PAOs (DNPAOs) that could use both nitrate and oxygen as terminal electron acceptors. Phosphorus uptake efficiency could be attained under anoxic period ranging from 28.7%-96.7% in an anaerobic/anoxic/aerobic system. Experimental results showed that nitrate concentration and retention time of anoxic/aerobic process were the key factors affecting the course of denitrifying dephosphatation.展开更多
The denitrifying sulfide removal(DSR) process with bio-granules comprising both heterotrophic and autotrophic denitrifiers can simultaneously convert nitrate, sulfide and acetate species into di-nitrogen gas, elementa...The denitrifying sulfide removal(DSR) process with bio-granules comprising both heterotrophic and autotrophic denitrifiers can simultaneously convert nitrate, sulfide and acetate species into di-nitrogen gas, elemental sulfur and carbon dioxide, respectively, at high loading rates. This study has determined that the reaction rate of sulfide oxidized into sulfur could be enhanced in the presence of 1,2-naphthoquinone-4-sulphonate(NQS). The presence of NQS mitigated the inhibition effects of sulfide species on denitrification. Furthermore, the reaction rates of nitrate and acetate to nitrogen gas and CO_2, respectively, were also promoted in the presence of NQS, thereby enhancing the performance of DSR granules. The advantages and disadvantages of applying the NQS-DSR process are discussed.展开更多
基金the National Key Project of Scientific and Technical Supporting Program of Ministry of Science and Technology ofChina(2006BAC19B03)Academic Human Resources Development in Institutions of Higher Leading under the Jurisdiction ofBeijing Municipalitythe Specialized Research Fund for the Doctoral Program of Higher Education of China(20060005002).
文摘Sequence hybrid biological reactor （SHBR） was proposed, and some key control parameters were investigated for nitrogen removal from wastewater by simultaneous nitrification and denitrification （SND） via nitrite. SND via nitrite was achieved in SHBR by controlling demand oxygen （DO） concentration. There was a programmed decrease of the DO from 2.50 mg·L^-1 to 0.30 mg·L^-1, and the average nitrite accumulation rate （NAR） was increased from 16.5% to 95.5% in 3 weeks. Subsequently, further increase in DO concentration to 1.50 mg·L^-1 did not destroy the partial nitrification to nitrite. The results showed that limited air flow rate to cause oxygen deficiency in the reactor would eventually induce only nitrification to nitrite and not further to nitrate. Nitrogen removal efficiency was increased with the increase in NAR, that is, NAR was increased from 60% to 90%, and total nitrogen removal efficiency was increased from 68% to 85%. The SHBR could tolerate high organic loading rate （OLR）, COD and ammonia-nitrogen removal efficiency were greater than 92% and 93.5%, respectively,, and it even operated under low DO concentration （0.5 mg·L^-1） and maintained high OLR （4.0 kg COD·m^-3·d^-1）. The presence of biofilm positively affected the activated sludge settling capability, and sludge volume index （SVI） of activated sludge in SHBR never hit more than 90 ml·L^-1 throughout the experiments.
基金National Natural Science Foundation of China(NO.50521140075)
文摘The study presented the method for isolating the heterotrophic nitrifiers and the characterization of heterotrophic nitrification. When influent Ammonia nitrogen concentration was 42. 78 - 73. 62 mg/L. The average ammonia nitrogen removal rate was 81.32% from the bioceramics reactor. Sodium acetate and ammonium chloride were used as carbon and nitrogen source. The COD removal rates by microorganisms of strain wgy21 and wgy36 were 56.1% and 45.45%, respectively. The TN removal rates by microorganisms of strain wgy21 and wgy36 were 65.85% and 67. 98%, respectively. At the same time, the concentration of ammonium nitrogen was with the removal rates of 75.25% and 84.96%, and it also had the function of producing NO2 - N. Sodium acetate and sodium nitrite were used as carbon and nitrogen source. Through the 12 days of the aerobic culture, the COD femoral rates by microorganisms of strain wgy21 and wgy36 were 29.25% and 22.08%, respectively. NO2 -N concentration decreased slowly. Comparison, similarity of wgy21 and many Acinetobacter sp. ≥99%, similarity of wgy36 and many Acinetobacter sp. ≥99%. Refer to routine physiologicalbiochemical characteristic determination, further evidences showed that wgy21 and wgy36 belong to Acinetobacter sp., respectively.
基金Sponsored by the National Natural Science Foundation of China(Grant No.50521140075)
文摘A method about the isolation of heterotrophic nitrosobactria and the characteristics of heterotrophic nitrosobactria were studied.It can be seen from the fluorescence in situ hybridization results of the bio-membrane sample from the bio-ceramic reactor,the spots of green nitrosobacteria are obviously more than those of orange nitrobacteria.Two heterotrophic nitrobacteria were isolated from the bio-ceramic reactor.By sequencing 16SrDNA and establishing the phylogenic tree,they were identified physiologically and biochemically as Pseudomonas sp..After 12 d,the COD removal efficiency of wgy55 and wgy68 were 45.03% and 50.85%,the NH4-N removal efficiency of them were 80.12% and 85.93%,and the TN removal efficiency of them were 69.71% and 64.7%.The final concentration of NO2-N of wgy55 and wgy68 was 0.753 mg/L and 0.601 mg/L,and that of NO3-N was 3.21 mg/L and 3.38 mg/L.These results show that wgy55 and wgy68 have the capability of nitrification and they are heterotrophic nitrobacteria.
基金Sponsored by the National Natural Science Foundation of China(Grant No50008014)
文摘This study was conducted to verify and discuss the denitrifying dephosphatation under different levels of nitrate concentration and retention time of anoxic/aerobic process in a Sequencing Batch Reactor (SBR). The results of tests demonstrated that there were two kinds of phosphorus-accumulating organisms (PAOs) in the biological excess phosphorus removal (BEPR) system. One was non-DNPAOs that could only use oxygen as terminal electron acceptors, the other was denitrifying PAOs (DNPAOs) that could use both nitrate and oxygen as terminal electron acceptors. Phosphorus uptake efficiency could be attained under anoxic period ranging from 28.7%-96.7% in an anaerobic/anoxic/aerobic system. Experimental results showed that nitrate concentration and retention time of anoxic/aerobic process were the key factors affecting the course of denitrifying dephosphatation.
基金supported bythe National Natural Science Foundation of China under Grant No. 21307160the Natural Science Foundation of Shandong Province under Grant No. ZR2013EEQ030
文摘The denitrifying sulfide removal(DSR) process with bio-granules comprising both heterotrophic and autotrophic denitrifiers can simultaneously convert nitrate, sulfide and acetate species into di-nitrogen gas, elemental sulfur and carbon dioxide, respectively, at high loading rates. This study has determined that the reaction rate of sulfide oxidized into sulfur could be enhanced in the presence of 1,2-naphthoquinone-4-sulphonate(NQS). The presence of NQS mitigated the inhibition effects of sulfide species on denitrification. Furthermore, the reaction rates of nitrate and acetate to nitrogen gas and CO_2, respectively, were also promoted in the presence of NQS, thereby enhancing the performance of DSR granules. The advantages and disadvantages of applying the NQS-DSR process are discussed.
